sgl-project/sglang · error · ValueError

Model architectures {architectures} failed to be inspected.

Error message

Model architectures {architectures} failed to be inspected. Please check the logs for more details.

What it means

Raised by _raise_for_unsupported when at least one requested architecture IS in the supported list, yet inspect_model_cls still failed to return a class for it — meaning registration exists but loading/inspection of the class errored (see the subprocess error) or returned nothing. It directs you to the logs for the underlying failure.

Source

Thrown at python/sglang/multimodal_gen/runtime/models/registry.py:347

        if isinstance(model_cls, str):
            split_str = model_cls.split(":")
            if len(split_str) != 2:
                msg = "Expected a string in the format `<module>:<class>`"
                raise ValueError(msg)

            model = _LazyRegisteredModel(
                module_name=split_str[0], class_name=split_str[1]
            )
        else:
            model = _RegisteredModel.from_model_cls(model_cls)

        self.registered_models[model_arch] = model

    def _raise_for_unsupported(self, architectures: list[str]) -> NoReturn:
        all_supported_archs = self.get_supported_archs()

        if any(arch in all_supported_archs for arch in architectures):
            raise ValueError(
                f"Model architectures {architectures} failed "
                "to be inspected. Please check the logs for more details."
            )

        raise ValueError(
            f"Model architectures {architectures} are not supported for now. "
            f"Supported architectures: {all_supported_archs}"
        )

    def _try_load_model_cls(self, model_arch: str) -> type[nn.Module] | None:
        if model_arch not in self.registered_models:
            return None

        return _try_load_model_cls(model_arch, self.registered_models[model_arch])

    def _try_inspect_model_cls(self, model_arch: str) -> _ModelInfo | None:
        if model_arch not in self.registered_models:
            return None

View on GitHub (pinned to 0132848349)

Solutions

1. Check preceding log lines for the inspection/load failure for that architecture (often the same root cause as the subprocess RuntimeError)
2. Verify the lazy '<module>:<class>' target still imports: python -c 'from m import C; print(C)'
3. Re-register the model with a corrected target or pass the class directly
4. If the class exists but inspection filters it out (abstract/wrong base), fix the class or its registration

from importlib import import_module
mod, cls = lazy_ref.split(':')
getattr(import_module(mod), cls)  # fails fast if inspection would fail

try:
    model_cls = registry.resolve_model_cls(config)
except ValueError as e:
    if 'failed to be inspected' in str(e):
        log.error('registered but broken model; check earlier subprocess logs')
    raise

When it happens

Trigger: Calling inspect_model_cls or resolve_model_cls with architectures=['FooModel'] where 'FooModel' appears in get_supported_archs(), but _try_load_model_cls returned None — e.g. the lazy module:class import failed silently or the subprocess inspection crashed.

Common situations: A model registered via lazy string whose module was renamed; partially failing registration in a plugin; an architecture registered but its inspection skipped due to a prior exception that was caught and logged.

Related errors

• Model architectures {architectures} are not supported for no
• scalar_type_id {scalar_type_id} doesn't exists.
• No kernels registered for op {op!r}
• No '{backend.value}' backend registered for op {op!r}
• pipeline_cls must inherit from ComposedPipelineBase

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/1077ffcc7f3c9ddc. Report an issue: GitHub.